December 4, 2009

Malleable Cast Iron Property

Malleable Cast Iron is the traditional material for manufacturing pipe fittings whose characteristics make it as ideal choice. It is an iron-carbon alloy which combines the outstanding properties of cast iron and steel to produce a material which can still be cast but has improved strength and ductility. It also allows the production of complex shapes combined with a thin wall section.

In its cast state it is very hard and brittle and unsuitable for most engineering applications. A controlled heat treatment process (annealing) is applied to the cast material which changes the structure and reduces the carbon content. The resulting microstructure gives a material which is less hard, no longer brittle and now has good malleable and ductile properties while retaining a sufficiently high strength.

Types

 

malleable iron metallography

Malleable Iron Metallography-Blackheart structure 70X –uniform carbon distribution

 

 

There are two distinct types of malleable cast iron which are dependent mainly on the annealing method used. Their names result from the different visual appearances at the fracture surfaces: Whiteheart malleable iron and Blackheart malleable iron.

Blackheart malleable iron is usually annealed in an inert atmosphere (protective gas or vacuum) and has a uniform microstructure. The higher carbon content is everly distributed throughout the structure.

 Material grade and properties:

Within the material types, a number of different grades are possible. The grades are defined by:

ü     Material type: blackheart and whiteheart

ü     Minimum tensile strength (MPa)

ü     Percentage elongation of a standard test piece.

Materials compare:

Standard

Grade

Tensile strength

(MPa)

Yield Strength

(MPa)

Elongation

(%)

Hardness (HB)

GB 9440-88

KTH300-6

300

6

150

KTH330-8

330

8

KTH350-10

350

200

10

NBR 6590

FMP-30006

300

6

149

FMP-35012

350

200

12

EN1562

EN-GJMB-300-6

300

6

150

EN-GJMB-350-10

350

200

10

150

ISO 5922

BS 6681

B30-06

300

6

150

B32-12

320

190

12

B35-06

350

200

10

DIN 1692

GTS-35-10

350

200

10

150

ASTM A197

275

200

5(50mm)

Material ,
One Comment
  1. Malleable casting requiremnts of the parts so plz how many rates per kg.every month 16 metric tonnes.
    send us quotes.

    RAJESH THAKAR
    RAJKOT INDIA

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